The easy was to convert from data+parity to data is to & your input with 0x7F. Note that this destroys any benifit the parity might have (in this case, none).

If you've got a bunch of data in $data, and want to strip the high bit, try $data = chr(0x7F) x length($data);.

Note that I suspect your actual problem has little to do with parity vs non-parity, but rather with utf-8 encoding. I know of nowhere in perl that cares about parity.